The world’s online shopping giants are following smaller web retailers into what might appear to be the merchandising past. Amazon, Alibaba and most recently JD.com, are operating brick-and-mortar stores, joining companies such as the formerly web-only Warby Parker and Outdoor Voices and reoccurring pop-up events by the likes of Gymshark and Aday. Even Tencent, the Chinese games and social media giant, is doing deals in retail.